My 11 year old printed and sold spinner's at his school last year. One of the more popular Father's Day Spinners was the attached Mustache Spinner we designed. It has been designed to get decent blance from a two weighted spinner. It makes for a great Father's Day gift for the dad who has almost everything.The design takes three 608 (22mm x 7mm) skateboard bearings. We used the Comfy Caps:https://www.thingiverse.com/thing:2319653